PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
Contact: Franklin O'Donnell
EMBARGOED FOR RELEASE SATURDAY, NOVEMBER 20, 1993
A Jet Propulsion Laboratory researcher has used modern
infrared imaging technology to reveal previously invisible
details on fragments of the Dead Sea Scrolls.
In the project, Dr. Gregory Bearman used a solid-state
sensor and computer image-processing to examine fragments from
the scrolls, a collection of 2,000-year-old manuscripts found in
caves on the Dead Sea.
"This approach allows us to see details that are invisible
using traditional photography on film," said Bearman.
"Archeology is just beginning to learn about digital imaging
technology, and it should prove to be a very powerful tool."
Bearman describes his work in a paper presented November 20
at a meeting of the American Academy of Religion/Society of
Biblical Literature in Washington, D.C.
Co-authors working with him included Dr. Bruce Zuckerman of
the University of Southern California, Ken Zuckerman of West
Semitic Research and Joseph Chiu of the California Institute of
Technology. Also collaborating on the project was the Ancient
Biblical Manuscript Center in Claremont, Calif.
Discovered in the 1940s and 1950s, the Dead Sea Scrolls
include thousands of fragments in Hebrew, Aramaic and Greek
written on sheepskin and other materials. The scrolls encompass
a variety of religious literature and are believed to have been
left by a Jewish community living near the Dead Sea from about
the 2nd century B.C. to the 1st century A.D.
Because of their great age and exposure to elements after
discovery, some of the scrolls have deteriorated and are mostly
impossible to read with the naked eye. The black ink typically
cannot be distinguished from the blackened parchment.
Scholars for many years have used film-based infrared
photography as a way of revealing the scrolls' invisible
characters. That technique, however, is limited by the nature of
infrared film.
"A camera using infrared film with a conventional filter
will see continuously from the visible spectrum out into the
infrared spectrum," Bearman explained. "That has proven
successful in revealing some of the scrolls' content, but in some
cases text is still not visible.
"What digital infrared imaging allows us to do is to look at
the scrolls in a narrow wavelength band," he added. "In some
cases this reveals detail which a film-based camera looking at a
broader wavelength spectrum cannot see."
Infrared films using a conventional filter, for example, are
sensitive to light from the red end of the visible spectrum --
corresponding to a wavelength of about 700 nanometers -- out into
the infrared range to 900 nanometers.
"In our work we found that the parchment of the Dead Sea
Scrolls is more reflective than the ink in the range of about 800
to 1,000 nanometers, which explains why cameras using those films
and filters have been fairly successful," Bearman said.
"In some cases, however, text remains obscured when imaged
in this wavelength range," he added. "We may be able to see it,
however, by using a charge-coupled device (CCD) digital camera
that looks at the document in the 1,000- to 3,000-nanometer
range, much farther in the infrared than film."
That was the case when Bearman and his colleagues used their
imaging equipment on a Dead Sea Scrolls fragment lent by the
Getty Conservation Institute, from a document called the Genesis
Apocryphon.
To the naked eye, the fragment appears to have been
completely ruined over time, with any vestige of text
obliterated. Film-based infrared photography, however, reveals a
series of largely illegible characters in one portion of the
fragment.
When the researchers imaged the fragment with a CCD camera
in the 900- to 1,000-nanometer wavelength range, they obtained
higher contrast images than is possible with film, said Bearman.
"On part of the fragment, the text is covered by a parchment
flap that remained stuck when the scroll was unrolled," he added.
"By looking at this portion with a CCD camera in the 1,000- to
3,000-nanometer spectral range, we can make out another word of
text which is invisible to either film-based or CCD imaging in
the 800- to 1,000-nanometer range."
In addition, the researchers used their equipment to examine
several Greek papyri -- text written on strips cut from the stems
of marsh plants -- that are more recent than the Dead Sea
Scrolls.
According to Bearman, his team used an "off-the-shelf"
infrared camera using a CCD sensor, combined with a frame grabber
and computer workstation.
Further archeological research would be enhanced, he said,
by building a system that would optimize imaging sensitivity at
selected wavelengths.
#####
Note to Reporters: Dr. Gregory Bearman may be reached through
November 21 at the Washington, D.C., Sheraton Hotel, (202) 328-
2000. Thereafter he may be reached at his JPL office, (818) 354-
3285.
Note: An image file illustrating this story is available from the
JPL Info public access computer site -- via Internet by anonymous
ftp to jplinfo.jpl.nasa.gov (137.78.104.2) or by dialup modem to
+1 (818) 354-1333 -- as filename DEADSEA.GIF in the directory
"images."
11-18-93 FOD
# 1537